Study on combustion characteristics of swirl premixed combustor

Abstract

Taking a certain type of combustion chamber as the research object, the numerical simulation is carried out by using RANS (Reynolds averaged Navier-stokes) and LES (large eddy simulation), and the simulation results of the two numerical methods are compared and analyzed. The research results show that the RANS calculation results can reflect the main flow field characteristics in the combustion field, and have certain engineering significance. LES can reproduce specific flow field details such as the weak axial flow region, accurately simulate the location and strength of the shear layer, simulate the dynamic development process of flame, and capture the dynamic characteristics of the combustion flow field. Compared with RANS, LES has more obvious advantages in numerical simulation of the combustion flow field. Through calculation, the precessing vortex core under this working condition is composed of three relatively independent spiral vortex branches, which excites periodic velocity pulsation and pressure pulsation in the combustion chamber. LES captures the dominant frequency with the precession vortex core of 156 Hz.